Fix blobs on rect lattice and axis lim bug

When lattice is rect, the blob positions need to be flipped to match
the hexagons positions.

The axis limits were inverting the axis. I think the reason might be
related to matplotlib/matplotlib#8693. This is solved in this commit.

sompy/visualization/umatrix.py

@@ -73,6 +73,8 @@ def _set_blob(self, umat, coord, ax, X=None, Y=None, hex=False):
         blobs[:, 2] = blobs[:, 2] * sqrt(2)
         if hex:
             blobs[:, :2] = rectxy_to_hexaxy(blobs[:, :2].astype(int), X, Y)
+        else:
+            blobs[:, :2] = np.flip(blobs[:, :2], axis=1)
         sel_points = list()
 
         for blob in blobs:
@@ -89,10 +91,10 @@ def _set_blob(self, umat, coord, ax, X=None, Y=None, hex=False):
             sel_points.append(sel_point[:, 0])
             if hex:
                 ax.set_xlim([-0.5, umat.shape[1]])
-                ax.set_ylim([0.6, -((umat.shape[0] - 1) * sqrt(3)/2 + 0.6)])
+                ax.set_ylim([-(((umat.shape[0] - 1) * sqrt(3)/2) + 1/sqrt(3)), 1/sqrt(3)])
             else:
                 ax.set_xlim([-0.5, umat.shape[1] - 0.5])
-                ax.set_ylim([-0.5, umat.shape[0] - 0.5])
+                ax.set_ylim([umat.shape[0] - 0.5, -0.5])
 
 
     def show(self, som, distance=1, row_normalized=False, show_data=False,
@@ -113,7 +115,7 @@ def show(self, som, distance=1, row_normalized=False, show_data=False,
             warn("For hexagonal lattice, distance < sqrt(3) produces a null U-matrix.")
         umat = self.build_u_matrix(som, distance=distance, row_normalized=row_normalized)
         msz = som.codebook.mapsize
-        proj = som.project_data(som.data_raw)
+        proj = som._bmu[0]
         coord = som.bmu_ind_to_xy(proj)[:, :2]
         sel_points = list()